Estrogen is feeding this cancer. I was stage 3 with a physically measurable lump. I went on Letrozole before surgery and chemo, and my oncologist used calipers to measure the tumor monthly as it appeared to shrink. After 7 months I had a lumpectomy where they did discover dead cancer cells (alas, not enough). I resumed AI's after chemo/radiation and will complete/terminate Letrozole's 5 year plan on New Year's eve this year. Because of lymph node involvement I have a 25% chance the cancer will return, but as my oncologist was quick to point out it's a 75% chance it won't. I will be 70 in two months.